Redevelopment PTC UNITS units on society plot

Sir, our society is a private housing society .it is not a slum /chawl . the appointed developer to get higher fsi redevelopment under section 33(11) . the letter of intent shows one ptc tower consisting of 159 sra units on our plot. initially society passed minutes in sgbm and passed resolution that no ptc tenements on our plot and he agreed they wiil buy some plot elsewhere and make ptc tenements on it. developer informed society that at chandivali they buy plot. however letter of intent shows ptc tenements on society plot itself. the developer informed society that they will later on change it and no ptc tenements on your plot they wiil built on chandivali plot or buy built up tenements if available. the office bearers agreed but i feel the deal suspicious as why our society plot is mentioned on which ptc tenements will be made. i think it creates sra interest on our plot. sra shall also become part owner of this plot. the so called architect also state it is normal not to worry it can be changed later on etc etc/ kindly guide me in the matter . regards jayesh choksi